The present invention is directed to memory systems.
As the massive volumes of electronically stored and transmitted data (e.g., “big data”) continue to increase, so does the need for electronic data storage that is reliable and cost effective, yet quickly accessible (e.g., low latency). Specifically, more computing applications are requiring that increasingly larger data sets be stored in “hot” locations for high speed access. Certain non-volatile memory (NVM) storage technologies, such as magnetic hard disk drives (HDDs), can provide a reliable, low cost storage solution, yet with relatively high access latencies. Such storage technologies might be used for large volumes of data in “cold” locations that are not often accessed (e.g., data warehouses, archives, etc.). Other volatile or “dynamic” memory storage technologies, such as dynamic random access memory (DRAM), provide lower access latencies, and might be used in “hot” locations near a computing host (e.g., CPU) to offer fast access to certain data for processing. Yet, such storage technologies can have a relatively high cost and risk of data loss (e.g., on power loss). Solid state NVM, such as Flash memory, can offer an improved form factor and access latency as compared to a hard disk, yet still not approach the access latency of DRAM.
In some cases, DRAM and Flash can be combined in a hybrid memory module to deliver the fast data access of the DRAM and the non-volatile data integrity (e.g., data retention) enabled by the Flash memory. One such implementation is the non-volatile dual in-line memory module (NVDIMM), which stores data in DRAM for normal operation, and stores data in Flash for backup and/or restore operations (e.g., responsive to a power loss, system crash, normal system shutdown, etc.).
Among other things, moving information stored at the NVM to volatile memory can be inadequate with conventional implementations, and improved techniques are desired.